Indoor Air Pollution Near Busy Roads

by / Wednesday, 07 September 2016 / Published in Environmental Testing, Healthy Building Inspections & Testing

Indoor Air Pollution Near Busy Roads

Freeways and other busy roads are sources of elevated auto emissions and Indoor Air Pollution. These emissions can be harmful to human health for both people on the roads and people working, walking, and living nearby. Nearly 20% of the United States population lives near a high volume road, and many workplaces and schools are located near these roadways.

Indoor Air Pollution

Pollutants associated with or directly emitted from vehicles on these roads include carbon monoxide, nitrogen oxides, fine particulate matter, ozone, sulfur oxides, and benzene, as well as hundreds of other chemicals. These pollutants, as well as other pollutants found near roadways have been associated with adverse health effects.

According to the EPA, adverse health effects that are associated with proximity to busy roads include asthma, cardiovascular disease, reduced lung function, impaired lung development in children, pre-term and low-birthweight infants, childhood leukemia, and premature death. An individual’s risk depends on his or her current health status, age, and the amount of exposure to air pollutants. People with asthma and other respiratory diseases, or are more susceptible to heart attacks and strokes are more at risk. Children and older adults are also among those at higher risk for health impacts from traffic emission pollutants.

indoor air pollution near busy roads


Exposure to indoor air pollution, however, varies based on specific conditions. Typically, pollutant concentrations decrease with distance away from traffic although the degree of this decrease varies. Wind direction and speed, terrain conditions, and time of day influence the distance and direction pollutants travel. Sound walls and natural and man-made wind breaks also have an impact on pollutant dispersion. Generally, the highest pollutant concentrations are found downwind of roadways, and tend to decrease to background levels within 500-600 feet of the roadway. Increased traffic, stop and go movement, and low wind speed usually result in increased pollutant levels.

Building design can also affect occupant pollution exposure. Maintaining and improving on filtration systems in mechanically ventilated buildings can reduce exposure. In addition, new buildings can be designed to minimize the time that at-risk people spend near roads by designing adequate filtration in ventilation systems and keeping occupants as far away from the roadways as possible when not indoors.

Steps can also be taken by individuals to reduce exposure to auto emissions. A Portable true HEPA filter installed in occupied areas can help remove particulate matter and possibly other pollutants from the air. Certain plants can also reduce pollutant concentrations. Walking/running/spending time away from busy roads will also decrease exposure to pollutants. Drivers and passengers on the roads can also reduce their exposure by closing car windows when in traffic or simply by avoiding busy and congested roads as much as possible.

More information on this topic can be found below:

From the EPA:

From the CDC:

3 Responses to “Indoor Air Pollution Near Busy Roads”

  1. Alex Stadtner says :

    Thanks for the comment. I’m fairly certain that most studies of air quality near roads will specify the approximate traffic rates on the roads under study. But I don’t know of a compilation of those results that would indicate how many cars it takes to tip the scales. Interesting. That would make a great thesis or dissertation for an aspiring environmental scientist!

  2. Stephanie Favila-Barnhardt says :

    This information is very helpful and eye opening. Our back yard faces a very busy road that is about 50 feet away from our house. I never thought about how the pollution from the cars could affect mine and my family’s health. I was always more concerned about noise pollution from the traffic. Are you aware of any research that shows how busy the road has to be;, ex: how many cars per hour have to pass by for it to be dangerous?

  3. […] information on how proximity to roadways impacts indoor air quality in our homes, see this blog on Indoor Air Pollution Near Busy […]

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